Technical Field
The present description relates to contact structures and gate structures used in semiconductor devices, and methods for forming contact structures and gate structures in semiconductor devices using subtractive etching.
Description of the Related Art
Modern integrated circuits are made up of literally millions of active devices such as transistors. Field effect transistors (FETs) are widely used in the electronics industry for switching, amplification, filtering and other tasks related to both analog and digital electrical signals. Most common among these are metal oxide semiconductor field effect transistors (MOSFET or MOS), in which a gate structure is energized to create an electric field in an underlying channel region of a semiconductor body, by which electrons are allowed to travel through the channel between a source region and a drain region of the semiconductor body. Continuing trends in semiconductor device manufacturing include a reduction in electrical device feature size (scaling). With increasing scaling, new processing sequences and methods may be required to avoid shorting of adjacent electrical devices.